O.J. Simpson jurors finally saw Wednesday how his genetic fingerprint was linked to murder: Dark blots on his DNA X-ray are similar to those from a blood drop found near the slashed bodies of his ex-wife and her friend.

“That pattern is consistent and looks to be the same as the pattern of Mr. Simpson’s (DNA),” biochemist Robin Cotton explained as many jurors looked at the DNA results flashed on a 7-foot courtroom screen.

Simpson didn’t pay attention to the screen, looking down at a notepad and occasionally talking with his attorneys.

Later, Cotton tied Simpson to the other end of the prosecution’s socalled trail of blood, telling jurors that DNA on a sock found at the foot of Simpson’s bed was consistent with his ex-wife’s.

The testimony about DNA results was long awaited. But Cotton’s matter-of-fact delivery - given to a jury that has been sequestered for four months and after 2 days of dense, scientific explanations about DNA robbed the moment of dramatic impact.

Cotton, director of Cellmark Diagnostics of Maryland, also testified that Simpson’s genetic “markers” were found in a blood drop collected from the foyer of his mansion the morning after the June 12 slayings of Nicole Brown Simpson and Ronald Goldman.

Prosecutors have suggested Simpson cut his hand while slashing the victims, leaving behind blood drops at the crime scene and his home, which is about two miles away. With no known eyewitnesses and no weapons recovered, prosecutors have built their case around DNA analysis of blood found at the crime scene, in Simpson’s Ford Bronco and at his estate.

Cotton said the genetic pattern suggested that the blood in Simpson’s foyer could not have come from the Simpsons’ two young children, Sydney and Justin, who often visited their father.

She also ruled out the possibility that the blood drop at the crime scene came from the children, who lived with Ms. Simpson and were asleep in her condominium at the time of the murders.

The defense has vigorously challenged DNA results, contending that evidence sent to Cotton’s Maryland lab for analysis was contaminated, mishandled or tampered with by police trying to frame Simpson.

During her presentation, Cotton gave each juror a transparency, or “autorad,” showing the genetic patterns of blood from Simpson, Ms. Simpson and Goldman. As she discussed results, most jurors chose to look at the courtroom screen, where the blots of those blood samples and comparisons to relevant evidence were blown up.

The similarities between Simpson’s blood and that of the blood taken from the murder scene and his house were obvious even to the untrained observer.